My totally un-biased view is that you'd be better off in 620s. Nothing to do with the fact that the only way I seem to attract any silverware is by relying on no-shows and crashers!
.....come to think of it, Paul Payne should do the same, and so should Phil H as soon as he's wrapped-up the championship good-and-proper... they've both got lovelly 620s and need to get some practice in for next year!
Then I might be on for just one win this year....just one win...that's all I ask!
Sorry Skids...would have included you in the list...but I assumed you'll be in the 583s 'till their death-nell is rung.